This invention relates to an electronic musical instrument and, more particularly, to a music synthesizer type electronic musical instrument utilizing frequency modulation of a tone signal with an audible frequency signal to enhance tonal effect of musical tones sounded.
Recently, music synthesizer type electronic musical instruments have been widely used by music players which incorporate a voltage-controlled tone signal synthesizing circuit arrangement including a voltage-controlled frequency-variable oscillator, voltage-controlled cutoff-frequency-variable filter, voltage-controlled gain-variable amplifier and time varying control waveform generators coupled to the voltage-controlled oscillator, filter and amplifier. The tone pitch, tone color and envelope of a musical tone being produced are controlled in accordance with the respective time-carrying control waveforms. Thus, such music synthesizer type electronic musical instruments are considerably effective to produce musical tones rich in variation as compared to conventional ordinary electronic musical instrument. However, in the musical synthesizer type electronic musical instruments, since a restricted number of waveforms of tone signals are used, the tone color of musical tones produced tends to be monotonous. This is because the harmonic content of musical tones is not satisfactorily great.